Washington ? The Obama administration’s senior health care official on Wednesday flatly rejected the idea of the government taking over the nation’s medical insurance system, saying the Obama administration does not want to assume management of health care coverage.

Kathleen Sebelius, in her first appearance before Congress since being confirmed as secretary of the Health and Human Services Department, said the administration wanted a so-called “public plan option” to encourage competition, not create a monopoly.

“Dismantling the private market and having an entirely public option, a single-payer system, I think is not something that the president supports,” Sebelius told the House Ways and Means Committee.

At the same time, she reaffirmed Obama’s commitment to creating a government-run insurance program to compete with private insurers — both to help cover the more than 46 million Americans currently without insurance and to encourage cost containment and better programs.

“Competition helps to promote innovation. It helps promote best practices and also can help to lower costs,” the former Kansas governor and state insurance commissioner said.

Sebelius’ testimony came as the Obama administration worked to defuse the politically explosive debate over creating a so-called public plan as part of a health system overhaul.

Many Republicans — as well as insurers — contend that a public plan would drive private insurance companies out of business, a claim repeated Wednesday.

“The rhetoric coming from the administration sounds good, sounds familiar — ‘If you like what you’ve got, you can keep it. We’re going to have more choice, more competition in health care,'” Rep. Paul Ryan, R-Wis., told Sebelius. “But when you look at what is being advocated here, in particular a public plan option, it just seems … you’re embracing contradictory principles.”

Sebelius responded that state governments for years have offered government employees a choice between a public insurance program and private insurance plans for their health care coverage.

“It can work very effectively, and does work very effectively,” she said, indicating that such arrangements could be a model for overhauling insurance markets nationally.